1. Field of the Invention
The present invention relates in general to computers, and more particularly to a method, system, and computer program product for throttling host throughput in computer storage subsystems.
2. Description of the Related Art
Computer systems may include a host which is connected to a computer subsystem, such as a computer storage subsystem. The host may store and access data from the computer storage subsystem over a communications channel having a maximum throughput. Generally, the throughput is measured in data passed through the channel per a certain time period, such as bytes-per-second (B/sec). Computer storage subsystems may include a variety of components such as virtual tape storage systems, where hard disk drive storage is used to emulate tape drives and tape cartridges. In other storage subsystems, hard disk drives may be configured in a redundant array of independent disks (RAID) typology.
While the communications channel between the host and the storage subsystem carries a maximum throughput, in certain situations it may be desirable to limit or “throttle” the throughput. For example, it may be desirable to throttle certain host throughput to an amount less than the maximum throughput for a certain amount of time. For example, a user may purchase a certain amount of host throughput. As a result, it is desirable to limit the host throughput to the purchased amount.